Bulk glass steel with high glass forming ability

ABSTRACT

The present disclosure provides specified ranges in the Fe—Mo—Ni—Cr—P—C—B alloys such that the alloys are capable of forming bulk glasses having unexpectedly high glass-forming ability. The critical rod diameter of the disclosed alloys is at least 10 mm.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication No. 61/847,973, entitled “Bulk Glass Steel with High GlassForming Ability”, filed on Jul. 18, 2013, which is incorporated hereinby reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to Fe—Mo—Ni—Cr—P—C—B alloys capable offorming bulk metallic glass rods with diameters greater than 10 mm andas large as 13 mm or larger.

BACKGROUND

Bulk-glass forming Fe—Mo—Ni—Cr—P—C—B alloys capable of forming bulkmetallic glass rods with diameters as large as 6 mm have been disclosedin U.S. application Ser. No. 12/783,007, entitled “Tough Iron-Based BulkMetallic Glass Alloys”, filed on May 19, 2010, the disclosure of whichis incorporated herein by reference in its entirety. In this earlierpatent application, Fe—Mo—P—C—B based compositions with a Mo content ofbetween 2 and 8 atomic percent, P content of between 5 and 17.5 atomicpercent, C content of between 3 and 6.5 atomic percent, B content ofbetween 1 and 3.5 atomic percent, and wherein the balance is Fe, werecapable of forming bulk metallic glass rods with diameters of at least 2mm. The earlier patent application also disclosed that when Ni and Crpartially substitute Fe, the glass-forming ability could be furtherimproved. Specifically, alloy composition Fe₆₈Mo₅Ni₅Cr₂P_(12.5)C₅B_(2.5)was disclosed as being capable of forming metallic glass rods of up to 6mm in diameter.

BRIEF SUMMARY

In the present disclosure, various Fe—Mo—Ni—Cr—P—C—B alloys aredisclosed capable of forming metallic glass rods with larger diametersthan previously disclosed. In various embodiments, the alloys arecapable of forming metallic glass rods with diameters greater than 10 mmand as large as 13 mm or larger. The present disclosure is also directedto metallic glasses formed of the alloys.

The disclosure is directed to an alloy represented by the followingformula (subscripts denote atomic percent):

Fe_((100-a-b-c-d-e-f))Mo_(a)Ni_(b)Cr_(c)P_(d)C_(e)B_(f)   (1)

In one embodiment of the alloy, a is between 4.5 and 6.75, b is between3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and 12.5, e isbetween 4.75 and 6.25,f is between 2.25 and 2.75. In some embodiments,the critical rod diameter of the alloy is at least 10 mm.

In another embodiment of the alloy, a is between 5.75 and 6.25, b isbetween 2.5 and 6.25, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4.75 and 6.25, f is between 2.25 and 2.75. In someembodiments, the critical rod diameter of the alloy is at least 10 mm.

In another embodiment of the alloy, a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 2.5 and 4, d is between 11.25 and 12.5,e is between 4.75 and 6.25,f is between 2.25 and 2.75. In someembodiments, the critical rod diameter of the alloy is 10 mm.

In another embodiment of the alloy, a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 10.75 and13.25, e is between 4.75 and 6.25,f is between 2.25 and 2.75. In someembodiments, the critical rod diameter of the alloy is at least 10 mm.

In another embodiment of the alloy, a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4 and 6.75, f is between 2.25 and 2.75. In someembodiments, the critical rod diameter of the alloy is at least 10 mm.

In another embodiment of the alloy, a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4.75 and 6.25,f is between 1.75 and 3.25. In someembodiments, the critical rod diameter of the alloy is at least 10 mm.

In another embodiment of the alloy, a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4.75 and 6.25, f is between 2.25 and 2.75. In someembodiments, the critical rod diameter of the alloy is at least 12 mm.

In another embodiment of the alloy, the sum of d, e, and f is between19.25 and 20.75. In some embodiments, the critical rod diameter of thealloy is at least 11 mm.

In another embodiment of the alloy, the sum of d, e, and f is between19.5 and 20.5. In some embodiments, the critical rod diameter of thealloy is at least 12 mm.

In yet another embodiment, up to 1 atomic percent of P is substituted bySi.

In yet another embodiment, up to 2 atomic percent of Fe is substitutedby Co, Ru, or combinations thereof.

In yet another embodiment, the melt is fluxed with a reducing agentprior to rapid quenching.

In yet another embodiment, the melt is fluxed with boron oxide prior torapid quenching.

In yet another embodiment, the melt temperature prior to quenching is atleast 1300° C.

In yet another embodiment, the melt temperature prior to quenching is atleast 1400° C.

In yet another embodiment, quenching the molten alloy comprisesinjecting or pouring the molten alloy into a metal mold.

In yet another embodiment, the notch toughness, defined as the stressintensity at crack initiation measured on a 3 mm diameter rod containinga notch with length between 1 and 2 mm and root radius between 0.1 and0.15 mm is at least 40 MPa m^(1/2).

In yet another embodiment, the compressive yield strength is at least3000 MPa.

In yet another embodiment, the shear modulus is 60 GPa or less.

In yet another embodiment, a wire made of such glass having a diameterof 0.25 mm can undergo macroscopic plastic deformation under bendingload without fracturing catastrophically.

The disclosure is also directed to alloy compositionsFe₆₇Mo₅Ni₅Cr₃P_(12.5)C₅B_(2.5),Fe_(66.5)Mo₅Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₆Mo₅N₁₅Cr₄P_(12.5)C₅B_(2.5),Fe₆₇Mo_(4.5)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₆Mo_(5.5)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),Fe_(65.5)Mo₆Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₅Mo_(6.5)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),Fe_(64.5)Mo₇Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₈Mo₆Ni_(2.5)Cr_(3.5)P_(12.5)C₅B_(2.5),Fe_(67.5)Mo₆Ni₃Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C₅B_(2.5),Fe_(66.5)Mo₆Ni₄Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₆Mo₆Ni_(4.5)Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₅Mo₆Ni_(5.5)Cr_(3.5)P_(12.5)C₅B_(2.5),Fe_(64.5)Mo₆Ni₆Cr_(3.5)P_(12.5)C₅B_(2.5),Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C₅B₂, Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C₅B₃,Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₃C_(4.5)B_(2.5),Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5),Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(11.5)C₆B_(2.5),Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₁C_(6.5)B_(2.5),Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C₆B₂, Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C₅B₃,Fe_(67.5)Mo₆Ni_(3.5)Cr_(3.5)P_(11.5)C_(5.5)B_(2.5),Fe_(66.5)Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C_(5.5)B_(2.5),Fe_(67.42)Mo_(6.04)N_(13.52)Cr_(3.52)P_(11.7)C_(5.36)B_(2.44), andFe_(66.58)Mo_(5.96)Ni_(3.48)Cr_(3.48)P_(12.3)C_(5.64)B_(2.56).

The disclosure is further directed to a metallic glass havingcomposition according to any of the above formulas and/or formed of anyof the foregoing alloys.

Additional embodiments and features are set forth in part in thedescription that follows, and in part will become apparent to thoseskilled in the art upon examination of the specification or may belearned by the practice of the disclosed subject matter. A furtherunderstanding of the nature and advantages of the present disclosure maybe realized by reference to the remaining portions of the specificationand the drawings, which forms a part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The description will be more fully understood with reference to thefollowing figures and data graphs, which are presented as variousembodiments of the disclosure and should not be construed as a completerecitation of the scope of the disclosure.

FIG. 1 provides a plot showing the effect of substituting Fe by Cr onthe glass forming ability of Fe_(70-x)Mo₅Ni₅Cr_(x)P_(12.5)C₅B_(2.5), inaccordance with embodiments of the present disclosure.

FIG. 2 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe_(70-x)Mo₅Ni₅Cr_(x)P_(12.5)C₅B_(2.5), in accordance with embodimentsof the present disclosure. Arrows from left to right designate theglass-transition and liquidus temperatures, respectively.

FIG. 3 provides a plot showing the effect of substituting Fe by Mo onthe glass forming ability ofFe_(71.5-x)Mo_(x)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5), in accordance withembodiments of the present disclosure.

FIG. 4 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe_(715-x)Mo_(x)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5), in accordance withembodiments of the present disclosure. Arrows from left to rightdesignate the glass-transition and liquidus temperatures, respectively.

FIG. 5 provides a plot showing the effect of substituting Fe by Ni onthe glass forming ability ofFe_(70.5-x)Mo₆Ni_(x)Cr_(3.5)P_(12.5)C₅B_(2.5), in accordance withembodiments of the present disclosure.

FIG. 6 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe_(70.5-x)Mo₆Ni_(x)Cr_(3.5)P_(12.5)C₅B_(2.5), in accordance withembodiments of the present disclosure. Arrows from left to rightdesignate the glass-transition and liquidus temperatures, respectively.

FIG. 7 provides a plot showing the effect of substituting P by B on theglass forming ability of Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(15-x)C₅B_(x), inaccordance with embodiments of the present disclosure.

FIG. 8 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(15-x)C₅B_(x), in accordance with embodimentsof the present disclosure. Arrows from left to right designate theglass-transition and liquidus temperatures, respectively.

FIG. 9 provides a plot showing the effect of substituting P by C on theglass forming ability of Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(17.5-x)C_(x)B_(2.5),in accordance with embodiments of the present disclosure.

FIG. 10 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(17.5-x)C_(x)B_(2.5), in accordance withembodiments of the present disclosure. Arrows from left to rightdesignate the glass-transition and liquidus temperatures, respectively.

FIG. 11 provides a plot showing the effect of substituting C by B on theglass forming ability of Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(8-x)B_(x), inaccordance with embodiments of the present disclosure.

FIG. 12 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(8-x)B_(x), in accordance with embodimentsof the present disclosure. Arrows from left to right designate theglass-transition and liquidus temperatures, respectively.

FIG. 13 provides a plot showing the effect of substituting Fe by P onthe glass forming ability ofFe_(79-x)Mo₆Ni_(3.5)Cr_(3.5)P_(x)C_(5.5)B_(2.5), in accordance withembodiments of the present disclosure.

FIG. 14 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glassesFe_(79-x)Mo₆Ni_(3.5)Cr_(3.5)P_(x)C_(5.5)B_(2.5), in accordance withembodiments of the present disclosure. Arrows from left to rightdesignate the glass-transition and liquidus temperatures, respectively.

FIG. 15 provides a plot showing the effect of varying the metal tometalloid ratio on the glass forming ability of(Fe_(0.8375)Mo_(0.075)Ni_(0.04375)Cr_(0.04375))_(100-x)(P_(0.6)C_(0.275)B_(0.125))_(x),in accordance with embodiments of the present disclosure.

FIG. 16 provides a plot showing calorimetry scans at a scan rate of 20°C./min for sample metallic glasses (Fe_(0.8375)Mo_(0.075)Ni_(0.04375)Cr_(0.04375))_(100-x)(P_(0.6)C_(0.275)B_(0.125))_(x), inaccordance with embodiments of the present disclosure. Arrows from leftto right designate the glass-transition and liquidus temperatures,respectively.

FIG. 17 provides an X-ray diffractogram verifying the amorphousstructure of a 13 mm metallic glass rod ofFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5), in accordance with embodimentsof the present disclosure.

FIG. 18 provides an image of an amorphous 11 mm rod of example metallicglass Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5).

FIG. 19 provides a compressive stress-strain diagram for examplemetallic glass Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5), in accordancewith embodiments of the present disclosure.

FIG. 20 provides a plot of the corrosion depth versus time in a 6M HClsolution for a 3 mm metallic glass rod having compositionFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5), in accordance with embodimentsof the present disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to alloys, metallic glasses, andmethods of making and using the same. In some aspects, the alloys aredescribed as capable of forming metallic glasses having certaincharacteristics. It is intended, and will be understood by those skilledin the art, that the disclosure is also directed to metallic glassesformed of the disclosed alloys described herein.

Description of Alloy Compositions

The disclosure is directed to Fe—Mo—Ni—Cr—P—C—B alloys and metallicglasses. In the present disclosure it was surprisingly discovered thatwithin specified ranges, Fe—Mo—Ni—Cr—P—C—B alloys demonstrateunexpectedly high glass-forming ability. In some embodiments,Fe—Mo—Ni—Cr—P—C—B alloy compositions with a Cr content of between 3 and4 atomic percent, Ni content of between 3 and 5 atomic percent, Mocontent of about 6 atomic percent, P content of between 11.5 and 12.5atomic percent, B content of about 2.5 atomic percent, C content ofbetween 5 and 6 atomic percent, and wherein the balance is Fe,demonstrate unexpectedly high glass forming ability (GFA). In variousembodiments, the critical rod diameter of the alloy is at least 13 mm orlarger. Although the glass forming ability is significantly higher,toughness remains essentially unchanged from the alloys disclosure inU.S. patent application Ser. No. 12/783,007.

In the present disclosure, the glass-forming ability of an alloy isquantified by the “critical rod diameter”, defined as largest roddiameter in which the amorphous phase can be formed when processed bythe method of water quenching a quartz tube with 0.5 mm thick wallcontaining the molten alloy.

Sample metallic glasses showing the effect of substituting Fe by Cr,according to the formula Fe_(70-x)Mo₅Ni₅Cr_(x)P_(12.5)C₅B₂₅, arepresented in Table 1 and FIG. 1. As shown, when the Cr atomic percent isbetween 2 and 4, the critical rod diameter of the alloy is at least 9mm, while when the Cr atomic percent is between 3 and 3.5, the criticalrod diameter is at least 10-mm. Differential calorimetry scans forexample metallic glass in which Fe is substituted by Cr are presented inFIG. 2.

TABLE 1 Sample metallic glasses demonstrating the effect of increasingthe Cr atomic concentration at the expense of Fe on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter [mm] 1 Fe₆₈Mo₅Ni₅Cr₂P_(12.5)C₅B_(2.5) 9 2Fe_(67.5)Mo₅Ni₅Cr_(2.5)P_(12.5)C₅B_(2.5) 9 3Fe₆₇Mo₅Ni₅Cr₃P_(12.5)C₅B_(2.5) 10 4Fe_(66.5)Mo₅Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 10 5Fe₆₆Mo₅Ni₅Cr₄P_(12.5)C₅B_(2.5) 10

Sample metallic glasses showing the effect of substituting Fe by Mo,according to the formula Fe_(71.5-x)Mo_(x)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5),are presented in Table 2 and FIG. 3. As shown, when the Mo atomicpercent is between 4.5 and 6.75, the critical rod diameter is at least10 mm, while when the Mo atomic percent is between 5.5 and 6.5, thecritical rod diameter is at least 11 mm. Differential calorimetry scansfor sample metallic glasses in which Fe is substituted by Mo arepresented in FIG. 4.

TABLE 2 Sample metallic glasses demonstrating the effect of increasingthe Mo atomic concentration at the expense of Fe on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter [mm] 6 Fe₆₇Mo_(4.5)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 10 4Fe_(66.5)Mo₅Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 10 7Fe₆₆Mo_(5.5)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 11 8Fe_(65.5)Mo₆Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 12 9Fe₆₅Mo_(6.5)Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 11 10Fe_(64.5)Mo₇Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 9

Sample metallic glasses showing the effect of substituting Fe by Ni,according to the formula Fe_(70.5-x)Mo₆Ni_(x)Cr_(3.5)P_(12.5)C₅B_(2.5),are presented in Table 3 and FIG. 5. As shown, when the Ni atomicpercent is between 3 and 5.5, the critical rod diameter of the alloy isat least 12 mm. Differential calorimetry scans for sample metallicglasses in which Fe is substituted by Ni are presented in FIG. 6.

TABLE 3 Sample metallic glasses demonstrating the effect of increasingthe Ni atomic concentration at the expense of Fe on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter [mm] 11 Fe₆₈Mo₆Ni_(2.5)Cr_(3.5)P_(12.5)C₅B_(2.5) 10 12Fe_(67.5)Mo₆Ni₃Cr_(3.5)P_(12.5)C₅B_(2.5) 12 13Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C₅B_(2.5) 12 14Fe_(66.5)Mo₆Ni₄Cr_(3.5)P_(12.5)C₅B_(2.5) 12 15Fe₆₆Mo₆Ni_(4.5)Cr_(3.5)P_(12.5)C₅B_(2.5) 12 8Fe_(65.5)Mo₆Ni₅Cr_(3.5)P_(12.5)C₅B_(2.5) 12 16Fe₆₅Mo₆Ni_(5.5)Cr_(3.5)P_(12.5)C₅B_(2.5) 12 17Fe_(64.5)Mo₆Ni₆Cr_(3.5)P_(12.5)C₅B_(2.5) 11

Sample metallic glasses showing the effect of substituting P by B,according to the formula Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(15-x)C₅B_(x), arepresented in Table 4 and FIG. 7. As shown, when the B atomic percent isbetween 1.75 and 3.25, the critical rod diameter of the alloy is atleast 10 mm, while when the B atomic percent is between 2 and 2.75, thecritical rod diameter is at least 11 mm. Differential calorimetry scansfor sample metallic glasses in which P is substituted by B are presentedin FIG. 8.

TABLE 4 Sample metallic glasses demonstrating the effect of increasingthe B atomic concentration at the expense of P on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter [mm] 18 Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₃C₅B₂ 11 13Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C₅B_(2.5) 13 19Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C₅B₃ 10

Sample metallic glasses showing the effect of substituting P by C,according to the formula Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(17.5-x)C_(x)B_(2.5),are presented in Table 5 and FIG. 9. As shown, when the C atomic percentis between 4.25 and 6.5, the critical rod diameter is at least 11 mm,while when the C atomic percent is between 5 and 6, the critical roddiameter is at least 13 mm. Differential calorimetry scans for samplemetallic glasses in which P is substituted by C are presented in FIG.10.

TABLE 5 Sample metallic glasses demonstrating the effect of increasingthe C atomic concentration at the expense of P on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter [mm] 20 Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₃C_(4.5)B_(2.5) 11 13Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C₅B_(2.5) 13 21Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) 13 22Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P_(11.5)C₆B_(2.5) 13 23Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₁C_(6.5)B_(2.5) 11

Sample metallic glasses showing the effect of substituting C by B,according to the formula Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(8-x)B_(x), arepresented in Table 6 and FIG. 11. As shown, when the B atomic percent isbetween 1.75 and 3.25, the critical rod diameter is at least 10 mm,while when the B atomic percent is between 2 and 2.75, the critical roddiameter is at least 11 mm. Differential calorimetry scans for samplemetallic glasses in which C is substituted by B are presented in FIG.12.

TABLE 6 Sample metallic glasses demonstrating the effect of increasingthe B atomic concentration at the expense of C on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter [mm] 24 Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C₆B₂ 11 21Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) 13 25Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C₅B₃ 10

Sample metallic glasses showing the effect of substituting Fe by P,according to the formulaFe_(79-x)Mo₆Ni_(3.5)Cr_(3.5)P_(x)C_(5.5)B_(2.5), are presented in Table7 and FIG. 13. As shown, when the P atomic percent is between 11 and 13,the critical rod diameter is at least than 11 mm, while when the Patomic percent is between 11.5 and 12.5, the critical rod diameter is atleast than 12 mm. Differential calorimetry scans for sample metallicglasses in which Fe is substituted by P are presented in FIG. 14.

TABLE 7 Sample metallic glasses demonstrating the effect of increasingthe P atomic concentration at the expense of Fe on the glass formingability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod Example CompositionDiameter[mm] 26 Fe_(67.5)Mo₆Ni_(3.5)Cr_(3.5)P_(11.5)C_(5.5)B_(2.5) 12 21Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) 13 27Fe_(66.5)Mo₆Ni_(3.5)Cr_(3.5)P_(12.5)C_(5.5)B_(2.5) 12

Sample metallic glasses showing the effect of varying the metal tometalloid ratio, according to the formula(Fe_(0.8375)Mo_(0.075)Ni_(0.04375)Cr_(0.04375))_(100-x)(P_(0.6)C_(0.275)B_(0.125))_(x),are presented in Table 8 and FIG. 15. As shown, when the metalloidatomic percent x is between 19 and 21, the critical rod diameter is atleast 11 mm, while when the metalloid atomic percent is between 19.5 and20.5, the critical rod diameter is at least 12 mm. Differentialcalorimetry scans for sample metallic glasses in which the metal tometalloid ratio is varied are presented in FIG. 16.

TABLE 8 Sample metallic glasses demonstrating the effect of increasingthe total metalloid concentration at the expense of metals on the glassforming ability of the Fe—Mo—Ni—Cr—P—C—B alloy Critical Rod ExampleComposition Diameter[mm] 28Fe_(67.42)Mo_(6.04)Ni_(3.52)Cr_(3.52)P_(11.7)C_(5.36)B_(2.44) 12 21Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) 13 29Fe_(66.58)Mo_(5.96)Ni_(3.48)Cr_(3.48)P_(12.3)C_(5.64)B_(2.56) 12

Among the compositions investigated in this disclosure, the alloyexhibiting the highest glass-forming ability is Example 21, havingcomposition Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5), which has acritical rod diameter of 13 mm. An x-ray diffractogram taken on thecross section of a 13 mm diameterFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) rod verifying its amorphousstructure is shown in FIG. 17. An image of an 11 mm diameterFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) metallic glass rod is shown inFIG. 18.

The measured shear, bulk, and Young's moduli, Poisson's ratio, density,notch toughness, and yield strength of sample metallic glassFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) (Example 21) are listed alongwith the critical rod diameter in Table 9. The notch toughness of allmetallic glass compositions according to the current disclosure isexpected to be at least 40 MPa m^(1/2), and the yield strength at least3000 MPa. The stress-strain diagram for sample metallic glassFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) is presented in FIG. 19.Lastly, below a certain thickness, the sample metallic glasses exhibitbending ductility. Specifically, under an applied bending load, thesample metallic glasses are capable of undergoing plastic bending in theabsence of fracture for diameters up to at least 0.25 mm.

TABLE 9 Engineering properties for sample metallic glassFe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) Critical rod diameter 13 mmDensity 7.52 g/cc Yield strength 3145 MPa Notch toughness 48 ± 1.7 MPam^(1/2) Shear modulus 59.4 GPa Bulk modulus 151.7 GPa Young's modulus157.6 GPa Poisson's ratio 0.327

Lastly, the Fe—Mo—Ni—Cr—P—C—B metallic glasses also exhibit goodresistance to corrosion. The corrosion resistance of example metallicglass Fe₆₇Mo₆Ni_(3.5)Cr_(3.5)P₁₂C_(5.5)B_(2.5) (Example 21) is evaluatedby immersion test in 6M HCl. A plot of the corrosion depth versus timeis presented in FIG. 20. The corrosion depth at approximately 933 hoursis measured to be about 306 micrometers. The corrosion rate is estimatedto be 2.87 mm/year. The corrosion rate of all metallic glasscompositions according to the current disclosure is expected to be under10 mm/year.

Description of Methods of Processing the Alloys

A method for producing the sample alloys involves inductive melting ofthe appropriate amounts of elemental constituents in a quartz tube underinert atmosphere. The purity levels of the constituent elements were asfollows: Fe 99.95%, Mo 99.95%, Ni 99.995%, Cr 99.996% (crystalline), P99.9999%, C 99.9995%, and B 99.5%. A method for producing metallic glassrods from the alloy ingots involves re-melting the ingots in quartztubes of 0.5-mm thick walls in a furnace at 1300° C. or higher, andpreferably at 1400° C. or higher, under high purity argon and rapidlyquenching in a room-temperature water bath. In general, amorphousarticles from the alloy of the present disclosure can be produced by (1)re-melting the alloy ingots in quartz tubes of 0.5-mm thick walls,holding the melt at a temperature of about 1300° C. or higher, andpreferably at 1400° C. or higher, under inert atmosphere, and rapidlyquenching in a liquid bath; or (2) re-melting the alloy ingots, holdingthe melt at a temperature of about 1300° C. or higher, and preferably at1400° C. or higher, under inert atmosphere, and injecting or pouring themolten alloy into a metal mold, preferably made of copper, brass, orsteel. Optionally, prior to producing an amorphous article, the alloyedingots can be fluxed with a reducing agent by re-melting the ingots in aquartz tube under inert atmosphere, bringing the alloy melt in contactwith the molten reducing agent and allowing the two melts to interactfor about 1000 s or longer at a temperature of about 1300° C. or higher,and preferably at 1400° C. or higher, and subsequently water quenching.

Test Methodology for Measuring Notch Toughness

The notch toughness of sample metallic glasses was performed on 3-mmdiameter rods. The rods were notched using a wire saw with a root radiusof between 0.10 and 0.13 μm to a depth of approximately half the roddiameter. The notched specimens were placed on a 3-point bending fixturewith span distance of 12.7 mm and carefully aligned with the notchedside facing downward. The critical fracture load was measured byapplying a monotonically increasing load at constant cross-head speed of0.001 mm/s using a screw-driven testing frame. At least three tests wereperformed, and the variance between tests is included in the notchtoughness plots. The stress intensity factor for the geometricalconfiguration employed here was evaluated using the analysis by Murakimi(Y. Murakami, Stress Intensity Factors Handbook, Vol. 2, Oxford:Pergamon Press, p. 666 (1987), the disclosure of which is incorporatedherein by reference).

Test Methodology for Measuring Yield Strength

Compression testing of sample metallic glasses was performed oncylindrical specimens 3 mm in diameter and 6 mm in length by applying amonotonically increasing load at constant cross-head speed of 0.001 mm/susing a screw-driven testing frame. The strain was measured using alinear variable differential transformer. The compressive yield strengthwas estimated using the 0.2% proof stress criterion.

Test Methodology for Measuring Density and Elastic Constants

The shear and longitudinal wave speeds of sample metallic glasses weremeasured ultrasonically on a cylindrical specimen 3 mm in diameter andabout 3 mm in length using a pulse-echo overlap set-up with 25 MHzpiezoelectric transducers. Densities were measured by the Archimedesmethod, as given in the American Society for Testing and Materialsstandard C693-93.

Test Methodology for Measuring Corrosion Resistance

The corrosion resistance of sample metallic glasses was evaluated byimmersion tests in hydrochloric acid (HCl). A rod of metallic glasssample with initial diameter of 2.97 mm, and a length of 18.86 mm wasimmersed in a bath of 6M HCl at room temperature. The density of themetallic glass rod was measured using the Archimedes method to be 7.52g/cc. The corrosion depth at various stages during the immersion wasestimated by measuring the mass change with an accuracy of ±0.01 mg. Thecorrosion rate was estimated assuming linear kinetics.

The metallic glasses described herein can be valuable in the fabricationof electronic devices. An electronic device herein can refer to anyelectronic device known in the art. For example, it can be a telephone,such as a mobile phone, and a land-line phone, or any communicationdevice, such as a smart phone, including, for example an iPhone®, and anelectronic email sending/receiving device. It can be a part of adisplay, such as a digital display, a TV monitor, an electronic-bookreader, a portable web-browser (e.g., iPad®), and a computer monitor. Itcan also be an entertainment device, including a portable DVD player,conventional DVD player, Blue-Ray disk player, video game console, musicplayer, such as a portable music player (e.g., iPod®), etc. It can alsobe a part of a device that provides control, such as controlling thestreaming of images, videos, sounds (e.g., Apple TV®), or it can be aremote control for an electronic device. It can be a part of a computeror its accessories, such as the hard drive tower housing or casing,laptop housing, laptop keyboard, laptop track pad, desktop keyboard,mouse, and speaker. The article can also be applied to a device such asa watch or a clock. Since the Fe—Mo—Ni—Cr—P—C—B metallic glasses aresoft magnets, they may be used, for example, as EMI shielding materialsin electronic components or devices.

Having described several embodiments, it will be recognized by thoseskilled in the art that various modifications, alternativeconstructions, and equivalents may be used without departing from thespirit of the disclosure. Those skilled in the art will appreciate thatthe presently disclosed embodiments teach by way of example and not bylimitation. Therefore, the matter contained in the above description orshown in the accompanying drawings should be interpreted as illustrativeand not in a limiting sense. Additionally, a number of well-knownprocesses and elements have not been described in order to avoidunnecessarily obscuring the disclosure. The following claims areintended to cover all generic and specific features described herein, aswell as all statements of the scope of the present method and system,which, as a matter of language, might be said to fall therebetween.

What is claimed:
 1. An alloy represented by the following formula(subscripts denote atomic percent):Fe_((100-a-b-c-d-e-f))Mo_(a)Ni_(b)Cr_(c)P_(d)C_(e)B_(f), wherein i) a isbetween 4.5 and 6.75, b is between 3 and 5.5, c is between 3.25 and3.75, d is between 11.25 and 12.5, e is between 4.75 and 6.25, f isbetween 2.25 and 2.75; ii) a is between 5.75 and 6.25, b is between 2.5and 6.25, c is between 3.25 and 3.75, d is between 11.25 and 12.5, e isbetween 4.75 and 6.25, f is between 2.25 and 2.75; iii) a is between5.75 and 6.25, b is between 3 and 5.5, c is between 2.5 and 4, d isbetween 11.25 and 12.5, e is between 4.75 and 6.25, f is between 2.25and 2.75; iv) a is between 5.75 and 6.25, b is between 3 and 5.5, c isbetween 3.25 and 3.75, d is between 10.75 and 13.25, e is between 4.75and 6.25,f is between 2.25 and 2.75; v) a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4 and 6.75,f is between 2.25 and 2.75; or vi) a isbetween 5.75 and 6.25, b is between 3 and 5.5, c is between 3.25 3.75, dis between 11.25 and 12.5, e is between 4.75 and 6.25, f is between 1.75and 3.25; and wherein the alloy has a critical rod diameter of at least10 mm.
 2. An alloy of claim 1, wherein a is between 4.5 and 6.75, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4.75 and 6.25, f is between 2.25 and 2.75.
 3. Analloy of claim 1, wherein a is between 5.75 and 6.25, b is between 2.5and 6.25, c is between 3.25 and 3.75, d is between 11.25 and 12.5, e isbetween 4.75 and 6.25, f is between 2.25 and 2.75.
 4. An alloy of claim1, wherein a is between 5.75 and 6.25, b is between 3 and 5.5, c isbetween 2.5 and 4, d is between 11.25 and 12.5, e is between 4.75 and6.25, f is between 2.25 and 2.75.
 5. An alloy of claim 1, wherein a isbetween 5.75 and 6.25, b is between 3 and 5.5, c is between 3.25 and3.75, d is between 10.75 and 13.25, e is between 4.75 and 6.25, f isbetween 2.25 and 2.75.
 6. An alloy of claim 1, wherein a is between 5.75and 6.25, b is between 3 and 5.5, c is between 3.25 and 3.75, d isbetween 11.25 and 12.5, e is between 4 and 6.75,f is between 2.25 and2.75.
 7. An alloy of claim 1, wherein a is between 5.75 and 6.25, b isbetween 3 and 5.5, c is between 3.25 and 3.75, d is between 11.25 and12.5, e is between 4.75 and 6.25, f is between 1.75 and 3.25.
 8. Analloy represented by the following formula (subscripts denote atomicpercent): Fe_((100-a-b-c-d-e-f))Mo_(a)Ni_(b)Cr_(c)P_(d)C_(e)B_(f),wherein a is between 5.75 and 6.25, b is between 3 and 5.5, c is between3.25 and 3.75, d is between 11.25 and 12.5, e is between 4.75 and 6.25,f is between 2.25 and 2.75, and wherein the alloy has a critical roddiameter of at least 12 mm.
 9. An alloy of claim 1, wherein the sum ofd, e, and f is between 19.25 and 20.75, and wherein the critical roddiameter of the alloy is at least 11 mm.
 10. An alloy of claim 1,wherein the sum of d, e, and f is between 19.5 and 20.5, and wherein thecritical rod diameter of the alloy is at least 12 mm.
 11. An alloy ofclaim 1, wherein up to 1 atomic percent of P is substituted by Si. 12.An alloy of claim 1, wherein up to 2 atomic percent of Fe is substitutedby Co, Ru, or combinations thereof.
 13. A metallic glass comprising analloy of claim
 1. 14. The metallic glass of claim 13, wherein themetallic glass has a notch toughness, defined as the stress intensityfactor at crack initiation when measured on a 3 mm diameter rodcontaining a notch with length ranging from 1 to 2 mm and root radiusranging from 0.1 to 0.15 mm, of at least 40 MPa m^(1/2).
 15. Themetallic glass of claim 13, wherein the metallic glass has a yieldstrength of at least 3000 MPa.
 16. A method of producing the metallicglass of claim 13 comprising: melting the alloy into a molten state; andquenching the melt at a cooling rate sufficiently rapid to preventcrystallization of the alloy.
 17. The method of claim 16, furthercomprising fluxing the melt with a reducing agent prior to quenching.18. The method of claim 17, wherein the reducing agent is boron oxide.19. The method of claim 16, wherein the melt temperature prior toquenching is at least 1300° C.
 20. The method of claim 16, the step ofquenching the molten alloy comprises injecting or pouring the moltenalloy into a metal mold.